After another 8.4 miles & 4463mAh, it died.  It burned 531mAh/mile.    2.6 of those were in 19m21s, slightly slower than the last 2.6 mile speed run, but also heading upwind.

The transmission was finally opened & cleaned.  The counter gear & pinion gear had a lot of loose dirt & were dry.  The differential gear was lubed & clean.  The holes for lubrication were hard to seal.  Electrical tape was replaced with a more tenacious adhesive, which might have liquefied & gotten into the gears, leading to the sudden drop in range.  The source of the dirt is mysterious.  Despite not sticking, electrical tape might have actually been a more effective seal.

The Tacon 2400kV is quite a well made beast, but bolts encasing it have corroded.  According to blog posts, when the lunchbox was new, the brushless motor burned 283mAh/mile.  The brushed motor burned 413mAh/mile.  All the conversions to increase the payload cost it.

3 years of inferior steering controllers vs new tires.

A rare pristineness worth documenting.  

Washing robots in this century is as important as washing cars was, in the last century.